Logo
  • Home
  • Stories »
    • Short Stories
    • Picture Stories
  • News »
    • Naija News
    • Entertainment Gist
    • Sport News
  • Education »
    • Examination Tips
    • Gidifans Examination
    • Jamb Updates
    • School News
    • Uncategorized

Waec 2018 Chemistry Obj And Theory Answers – May/June Expo

photo
Mr. Maraj
Post In Gidifans Examination Center (GEC)
1380

Solution Centre for All Examinations both WAEC/WASSCE/SSCE, NECO, NABTEB, JAMB (UTME), Post-UTME, WAEC GCE, NECO GCE, NABTEB GCE etc


ALWAYS SUBSCRIBE IF YOU WANT YOUR ANSWERS ON TIME.
NOTE: WE SETTLE SUBSCRIBERS BEFOR UPDATING HERE…

TELL YOUR FRIENDS ABOUT GIDIFANS NOW!!!!



Chemistry OBJ:
1ABDCBCABAC
11DACBBACCAA
21CBCDCDAAAB
31AABACBABAA
41DBBDCBCCDB



3ai)
H H H H H
| | | | |
H-C-C-C-C-C-C=C-H Heptene
| | | | | |
H H H H H H
3aii)
The sixth member of Allene C7H14 =
7(molecular mass of carbon) + 14(molecular mass of H)
= 7(12) + 14(1)
= 84 + 14 = 98gmol-¹
3aiii)
-Cracking is the breaking down of higher molecules into smaller molecules while reforming is the change in the functional group or activity of the compound.
-In cracking more than one product or component is formed. But in reforming one product can still be gotten.

3bi)
Enthalpy of Neutralization change is the heat change which offers when one mole of H+ from an acid reacts with one mole of OH- from an alkali to form one mole of water.
3bii)
Weigh about 100cm³ of dil HCL(aq) and that of KOH(aq) of equal volume and put each into a glass calorimeter. The temperature of the two Solutions are taken. The mean volume of the temperature of the acid and base taken. Then quickly transfer the alkali to the acid, turn and take the final temperature of the solution. Record the mass of the mixture. Find the temperature difference.
Total heat covered = mass × specific heat capacity × temperature change.

3ci)
I – copper
II – silver
3cii)
Because silver is below copper in the electrochemical series.
3ciii)
Oxidation – anode
Reduction – Cathode



2ai)
Collision theory states that the rate of a reaction depends on the rate of collision of the reactant molecules. Hence effective collision determines the rate of the reaction because it is the collision that leads to the formation of a product.

2aii)
When the rate of collision increases, the rate at which molecules collide with each other will also increase thereby making the kinetic energy of the molecules to also increase. The temperature will also increase because temperature is a measure of average kinetic energy.

2bi)
CLICK HERE TO VIEW THE DIAGRAM
2bii)
C2H5OH + 3O2 —->2CO2 + 3H2O
1mole of ethanol = 3moles of O2
2.5moles of ethanol will require 3 × 2.5/1 = 7.5moles of O2.
but 1 mole of gas = 22.4dm3
7.5moles = 7.5 × 22.4 = 168dm3 of O2.

2Ci)
Esterification is the formation of an Ester by the reaction between Alkanol and an acid.
2cii)
Two uses of alkanols
i)They are used as solvents for cellulose
ii)They are uses in making perfumes and cosmetics.
iii) They are used for quick drying of paints and nail varnishes.
2ciii)
Sodium Ethanoate

2di)
Tin
2dii )
This is because the galvanized plate is corrosion-resistant. It has a protective coating which prevents further oxidation of the metal.



1a)
Fermentation is the chemical breakdown of a substance by bacteria, yeasts, or other microorganisms, typically involving effervescence and the giving off of heat.
1aii)
disastase

1b)
i)colour change
ii)end point

1c)
1mole
c=n/v=1.0moldm^-3
V=10cm^3=0.01dm^3
n=cv=1.0moldm^-3*0.01dm^3
n=0.01mol of H2SO4
x—>0.01mol of H2SO4
x=56*0.01/1 = 0.56g
mass unreacted = (5-0.56)g=4.44g

1di)
copper (ii) tetraoxsulphate(iv)
1dii)
dyes

1e)
A catalyst increases the rate of a chemical by swinging it’s activation every.
1f)
i) CH3CooH + NH3 —->CH3CooH2 + H2O
ii) Ethanoamide

1g)
i)It doesn’t corrode easily.
ii)it doesn’t react with contain inside.
iiii)It can stand for a long period of time.

1h)
i)Sweet production industries
ii)perfume industries.

1i)
i)evaporation
ii)seeding

1j)
i)it increases the volume water in ocean and seas.
ii)It causes increase in rainfall and also corrode painted surfaces



4ai)
CLICK HERE TO VIEW THE DIAGRAM

4aii)
Na2SO3(aq) + 2HCl(aq)—–>2Nacl(aq)+H2O(s)+SO2(q)
4aiii)
dry the gas evolved by passing it through H2SO4 and collect it by downward delivery
4aiv)
because it is denser than air

4bi)
Dalton’s law of partial pressure states that in a mixture of gases, which do not react chemically together, a gas will exert a partial pressure, which is the pressure, it will exert if it is kept alone in the vessel.

4bii)
T1=12degree = 285k
P1=690mm Hg
V1=30cm^3
T2=273k
P2=760mmhg
V2=?
Using the general gas law
V1P1/T1 = V2P2/T2
V2=30*690*273/285*760
V2=261cm^3
V2=26cm^3

4ci)
Cl2(q)+H2O(i)——>HCL(aq)+HOCL(aq)
4cii)
litmus turn red because of the presence of the acid HCL

4di)
chlorine bromine iodine/increasing boiling point
4dii)
because water has two(2)ion pairs of electrons as compared to ammonia which has one



COMPLETED

If you like this story, please share it on Facebook, Twitter, Google+, Pinterest ETC.
…also don’t forget to leave a comment, we would very MUCH appreciate Your Comments On This Post Below. Thanks!
April 9, 2018
Related » Gidifans Examination Center (GEC)
photo
Waec 2018 Computer Studies Obj And Theory Answers – May/June Expo
photo
Waec 2018 Chemistry Practical Answers – May/June Expo
photo
Waec 2018 Yoruba, Hausa, Igbo Obj And Theory Answers – May/June Expo
photo
Waec 2018 English Language Obj, Essay And Oral Answers – May/June Expo
photo
Waec 2018 Biology Practical Answers – May/June Expo
» See More...
33 Comments
  1. Guest says:
    April 9, 2018 at 3:25 pm

    Please I need the waec answer tomorrow morning

    Reply
  2. Guest says:
    April 10, 2018 at 1:53 am

    I have subscribe for chemistry and I have not gotten the pin

    Reply
  3. Lim says:
    April 10, 2018 at 6:05 am

    Today is physics essay

    Reply
  4. Guest says:
    April 10, 2018 at 8:03 am

    have subscribe for the password link and am yet to recieve the password

    Reply
  5. abiola says:
    April 10, 2018 at 8:06 am

    When will the answer be out for chemistry

    Reply
  6. Wizy says:
    April 10, 2018 at 10:06 am

    Please we need chemistry answer now

    Reply
  7. Guest says:
    April 10, 2018 at 11:29 am

    Pls i need Chemistry

    Reply
  8. Guest says:
    April 10, 2018 at 11:33 am

    Pls help me with chemistry

    Reply
  9. Guest says:
    April 10, 2018 at 11:47 am

    pls

    Reply
  10. Guest says:
    April 10, 2018 at 12:09 pm

    i love this site

    .

    Reply
  11. Anonymous says:
    April 10, 2018 at 12:13 pm

    I need chemistry theory at now

    Reply
  12. Anonymous says:
    April 10, 2018 at 1:26 pm

    Bello

    Reply
  13. Anonymous says:
    April 10, 2018 at 1:44 pm

    Anything so far

    Reply
  14. Guest Lukas says:
    April 10, 2018 at 1:48 pm

    Gidifans don’t talk much… I like that, nice one the Gidis gidis…

    Reply
  15. Guest says:
    April 10, 2018 at 1:52 pm

    since I haven’t chemistry

    Reply
  16. Guest says:
    April 10, 2018 at 1:56 pm

    no time pls 1minz remaining pls

    Reply
  17. Anonymous says:
    April 10, 2018 at 2:11 pm

    pls we need your help

    Reply
  18. Guest says:
    April 10, 2018 at 2:48 pm

    kul

    Reply
  19. Guest says:
    April 10, 2018 at 3:22 pm

    this site is very brave

    Reply
  20. Guest says:
    April 10, 2018 at 4:13 pm

    gidi fans is good you guys saved me today keep up the good Work

    Reply
  21. Guest says:
    April 10, 2018 at 4:41 pm

    pls I need ur help on the remaining subjects

    Reply
  22. prince tosin says:
    April 10, 2018 at 5:52 pm

    thanks gidifans

    Reply
  23. Guest says:
    April 10, 2018 at 7:48 pm

    thanks be to.Almighty God
    may god help u

    Reply
  24. hamisu sani says:
    April 10, 2018 at 7:48 pm

    thanks be to.Almighty God
    may god help u

    Reply
  25. anonymous says:
    April 10, 2018 at 7:49 pm

    When did chemistry drop in this group

    Reply
  26. Guest says:
    April 10, 2018 at 10:09 pm

    group link please

    Reply
  27. Dolor Peter says:
    April 11, 2018 at 5:14 am

    Chemistry answer came last. Let the Civic be early. Thanks

    Reply
  28. Guest Dolor Peter says:
    April 11, 2018 at 5:16 am

    I need the pin for Civic

    Reply
  29. Sulaiman Adamu says:
    April 11, 2018 at 3:22 pm

    Thanks for your paticipation to give us the answer

    Reply
  30. Anonymous says:
    April 12, 2018 at 7:34 am

    Pls English

    Reply
  31. talented says:
    April 18, 2018 at 5:19 am

    Pls try nd be be sending d code on time pls sum of us cant tell phone to d hall

    Reply
  32. Guest says:
    April 19, 2018 at 8:24 am

    plz I need physics answer, and also the pin 4 all subject

    Reply
  33. Guest says:
    April 20, 2018 at 10:14 am

    Plz send chemistry theory number 9,12

    Reply
Please Leave a comment ;)
Click here to cancel reply.


Examination HelpDesk
WAEC 2018 Runz NECO 2018 Runz
WAEC
How to Make A/B/C's in Your 2018 Waec Examination - CLICK HERE
NECO
How to Make A/B/C's in Your 2018 Neco Examination - CLICK HERE
NABTEB 2018 Runz DAILY 2018 Runz
NABTEB
How to Make A/B/C's in Your 2018 Nabteb Examination - CLICK HERE
NABTEB
Exam Daily Subscription (Subject Prices) - CLICK HERE
Featured Posts
photo
Waec 2018 Government Obj And Theory Answers – May/June Expo

photo
All What You Need To Know About JAMB UTME Result Upgrade

photo
Waec 2018 Practical Specimens

photo
JAMB Cut off Marks 2018/2019 for all Nigerian Universities, Polytechnics and Colleges

photo
2018 WAEC SSCE May/June Timetable

Trending Stories
  • -Confession Of a Nigerian, 14year-Old-Boy, Well Endowed, Who Had S*x With His Mom’s Best Friend (5)
  • -The Day After Christmas (2)
  • -GoodBye My Love (4)
  • -Lagos Wedding Wahala (19)
  • -The Hell in Living in a Man’s World: My Tearful Tale (24)
  • -How Our Family Driver Dis-virgined me, Turned Me Into Nymphomaniac (8)
  • -Tochi (20)
  • -3 Sisters And A Corper (12)
  • -4Boys, 4Girls, 1WEEKEND (20)
  • -The Stranger I called FRIEND (21)
All Stories »
Advert
Recent Comments On Topics
Waec 2018 Government Obj And Theory Answers – May/June Expo - Guest
Waec 2018 Government Obj And Theory Answers – May/June Expo - bright
Waec 2018 Government Obj And Theory Answers – May/June Expo - Guest
Waec 2018 Literature (Drama And Poetry) Answers – May/June Expo - Mary
Waec 2018 Biology Obj And Theory Answers – May/June Expo - Guest
5 Nigeria Polytechnic That May Accept Below 180 Jamb Cut Off Mark - Guest
Waec 2018 Biology Obj And Theory Answers – May/June Expo - 08189443024
Waec 2018 Biology Obj And Theory Answers – May/June Expo - Guest
Waec 2018 Practical and Physical Geography Answers – May/June Expo - Anonymous
Waec 2018 Physics Obj And Theory Answers – May/June Expo - Idris umar suleiman
Copyright © 2018 Gidifans